1. Field of the Invention
The present invention relates to a door of a cabin having an entrance and provided in a construction machine such as a hydraulic shovel, the door adapted to open and close the entrance.
2. Description of the Background Art
FIG. 6 shows an example of a hydraulic shovel provided with a cabin 7 having a door, and FIGS. 7 through 9 show the cabin 7 with the door opened.
The hydraulic shovel is provided with a crawler-type lower propelling body 1, an upper slewing body 2 loaded on the lower propelling body 1 slewably around an axis perpendicular to the ground, and a working attachment 6 to be attached to the upper slewing body 2. The working attachment 6 has a boom 3, an arm 4 and a bucket 5. The cabin 7 is disposed on a left-side front portion of the upper slewing body 2.
In the present specification, “front and rear” and “left and right” are described based on a viewing direction of an operator seated in the cabin 7.
The cabin 7 has a cabin frame, an entrance 8 formed in the cabin frame to allow the operator to get in and out of the cabin through the entrance 8, and a door 9. The entrance 8 is formed in a front portion on a left surface of the cabin 7. The door 9, which is adapted to open and close the entrance 8, has a front end portion to be pivotally connected to a main body of the cabin 7 and a rear end portion so as to open and close the entrance 8.
The cabin frame has a front fringe portion located on the front side of the entrance 8 and a rear fringe portion located on the rear side of the entrance 8, the front and rear fringe portions attached with front and rear riding handles 10 and 11 respectively. Each of the front and rear riding handles 10 and 11, which is provided at an intermediate position of the cabin frame in respect of up and down directions, has a pair of upper and downward extending portions projecting from the corresponding fringe portion and a connecting portion vertically interconnecting respective ends of the projections, thus allowing the operator to get in and out of the cabin by gripping vertical portions of the front and rear riding handles 10 and 11.
The door 9, as also shown in FIG. 9, has a door frame 12 formed of a vertically extending pipe and a door glass 13 to be attached to the door frame 12. The cabin frame includes an intermediate pillar 14 located at an intermediate portion of the cabin frame in respect of front and rear directions. The door frame 12 has an upper end and a lower end to be attached to the intermediate pillar 14 via a pair of upper and lower hinges 15 and 15 pivotally around a vertical axis respectively. The door glass 13 pivots integrally with the door frame 12 to thereby open and close the entrance 8.
The pipe constituting the door frame 12 has been bent to form the door frame 12 into a shape having an upper straight portion and a lower straight portion each vertically extending and an intermediate portion located between the upper and lower straight portions and bulging from the upper and lower straight portions orthogonally to vertical directions. As shown in FIG. 9, a small clearance C2 is formed between the upper and lower straight portions, and the door glass 13; and a clearance C1 is formed between the intermediate portion and the door glass 13. The clearance C1 has a size larger than that of the clearance C2 and large enough to allow the operator to insert his fingers into the clearance C1 to grip the intermediate portion. The intermediate portion of the door frame 12, therefore, serves as a pulling handle portion 16 to be gripped by the operator to close the door 9 by a pulling operation from the inside of the cabin 7.
Although not illustrated, the cabin 7 is provided with, in addition to the pulling handle portion 16, an opening/closing handle to be operated in a direction of opening the door 9 from the inside of the cabin 7 and operated to open and close the door 9 on the outside of the cabin 7, and a catch mechanism for retaining the door 9 at both of the opening position and the closing position.
There has been found no document disclosing a door provided with the door frame 12 constituted of a pipe as described above. The technology relating to the above arrangement is disclosed in Japanese Unexamined Patent Publication No. 2009-215702.
The door 9 has a drawback that the operator may misuse the pulling handle portion 16 as the riding handle to thereby allow an unwanted mechanical load to be applied on the door frame 12 or on the door glass 13. Specifically, the pulling handle portion 16 is:
a) positioned at such a height position that the operator standing on the ground is likely to grip, as well as the intermediate portion of the rear riding handle 11;
b) positioned immediately behind the rear riding handle 11, and
c) provided with a vertically extending portion which is likely to be gripped by the operator, as well as the rear riding handle 11.
Furthermore, the pulling handle portion 16 is vertically longer than the rear riding handle 11 and has a shape of projecting outwardly when the door glass 13 is opened; this is intend to cause the operator to mistakenly grip the pulling handle portion 16 when getting in and out of the cabin.